The present invention relates to an electromagnetic device for accurate acoustic transduction of electrical audio amplifier current; for converting electrical energy into the physical energy of sound waves. More particularly, the present invention relates to a single-driver acoustic horn audio reproducer comprising a transducer element, or piston, mounted within a suspension sleeve/horn at a point allowing equal air pressure on both sides of a diaphragm mounted in the transducer element during operation.
Since it was first proved that recording sound on a tangible medium is possible, there have been numerous efforts to improve the quality of reproduction of recorded sound. These efforts include great advances in transcription methodology, but audio reproducers, or speakers, remain an area in which considerable room remains for improvement.
So far as is known, all audio speakers fail to translate the electrical signals produced by audio amplifiers faithfully as a result of a series of compromises in their construction, design, components, size, and purpose, all of which are generally a reflection of the price at which the speaker sells. Further, all audio reproducers exhibit frequency distortion because of a number of factors, including the non-rigid character of the material comprising the speaker diaphragm (sometimes referred to as "cone break-up"), improper acoustic impedance matching, biased magnetic structure, odd-order over/under resonances (which are caused both electromechanically and by the housing/bafflings of the loudspeaker), diaphragm suspension characteristics, and by the crossover networks necessitated by multi-driver systems.
The non-rigidity of the material comprising the diaphragm and acoustic impedance matching problems are two major sources of distortion. It is possible to minimize the distortion caused by these two sources. Sound reproduction of acceptable quality has been achieved in single-driver headphones designed for low power applications (less than 1 watt) in which sound pressure level and frequency response is optimal when worn close to the ear. When scaled up for use as a loudspeaker, however, the quality of sound reproduction by these devices in an open space deteriorates unless stationed within an acoustic horn.
It is, therefore, an object of this invention to provide improved high quality audio reproduction by minimizing physical distortion of the diaphragm and acoustic impedance matching problems.